The invention consists of a sealing device for a manhole intended to provide an hermetic seal for the access mouth with the aid of a lid that forms part of the assembly of the device.
The sealing device ensures the securing of the lid in the access mouth in order to prevent any infiltration of fluids from the outside or escape of gases from the interior.
Manholes currently include an access opening or mouth where a sealing lid is fitted in order to isolate the interior of the hole from the exterior in order to protect the contents of that hole.
The lid is normally associated with a sealing device that ensures the fastening of said lid in order to provide tightness and imperviousness in the seal so as to prevent any infiltration of fluids or gases from the outside to the interior.
Utility model No. 9800352 consists of a sealing device for underground tanks that includes a lid that fits into a frame provided in correspondence with the access mouth to the tank. This lid rests against a sealing O-ring housed in a perimetric groove in the frame. The sealing device basically consists of a crosspiece whose ends are associated with the frame, while at the same time a central screw threads onto this crosspiece in order to secure the lid against the O-ring, this latter being the element which, along with the lid, provides the tank with its imperviousness.
The device of utility model number 9800352 presents the drawback that, after a period of time, the imperviousness of the tank becomes reduced and the seal loses its effectiveness, mainly due to the weakness of the structure presented by the crosspiece where the securing screw threads into the lid, in such a way that, after a while, it becomes deformed and arches upwards, with which the pressure of the lid on the O-ring becomes reduced and the tank therefore loses its tightness.
Another drawback is that after a while, when the access lid is removed, the O-ring sticks to the lid, causing it to become dislodged from its position, which thereby creates the danger of the ring falling into the tank.
In order to achieve the objectives and to avoid the drawbacks mentioned in the above paragraphs, the sealing device for manholes is characterised in that it includes a new sealing joint with a profile that is clasped to at least a portion of the frame made in the mouth of the hole, a lid which will rest on said joint being secured on the frame. In this way, the joint will at all times remain on the frame without becoming detached from it when the lid is removed.
The device is also characterised in that the lower face of the lid includes a perimetric inclined band that in a complementary way makes contact against the sealing joint, thereby achieving a better seal.
Another improvement refers to the structure presented by the crosspiece wherein the screw is threaded for securing the lid. Unlike the crosspiece of the utility model mentioned in the previous section, this crosspiece does not arch when the screw is tightened, which means the imperviousness of the lid is not adversely affected.
Another characteristic of the invention consists of the means of linking the crosspiece on the frame of the access mouth to the interior of the hole. Thus, instead of the springs used in utility model No. 9800352, in the present invention a plurality of simple conventional mechanisms for quick locking and a plurality of lower stops are used, which substantially facilitate the extraction of the respective crosspiece. When the quick locking mechanisms are unlocked, the crosspiece rests on the lower stops.
Another improvement to the device refers to the fact that the frame includes means for preventing its deformation when the lid is secured and tightened.
In order to aid a better understanding of the invention, the description is accompanied by figures representing the object of the invention.